Alkaline dry batteries have been widely used as the power source for daily necessities, toys, hobby goods, game machines, and electronic devices such as portable music players. At present, size D to N and prismatic (9V) alkaline dry batteries are manufactured and on sale. However, when batteries are installed in electronic devices, they may be installed incorrectly with the positive terminal and the negative terminal reversed (hereinafter referred to as simply “installed reversely”).
As methods for preventing such reverse installation, attempts to improve battery structure have been made. For example, with respect to the end face of a cylindrical battery having a negative terminal, there has been proposed a structure in which the negative terminal is surrounded with a protrusion (Patent Document 1). Also, it has been proposed to provide insulating resin protrusions on the surface of a negative terminal (Patent Document 2). According to the methods described in Patent Documents 1 and 2, when a plurality of batteries are connected in series, it is possible to prevent the negative terminals of the batteries from being connected mistakenly.
It has also been proposed to improve device structure so that even if a battery is installed reversely, the terminals of the battery do not come into contact with the terminals of the device (Non-Patent Document 1).    Patent Document 1: Japanese Laid-Open Patent Publication No. Hei 9-147831    Patent Document 2: Japanese Laid-Open Patent Publication No. Hei 9-161762    Non-Patent Document 1: “A Guidebook for Safety Design of Battery Compartment and Terminals of Battery Operated Devices” (second edition)”, P. 7-12, edited and published by Battery Association of Japan (incorporated body)